More info needed! You've got quite a range of old, older, and different featured cameras there...to help you hone in on what would be best for you, we'd best be able to help by knowing your budget (both what you'd like to spend, and what you'd be willing to), what lens range you think you'd want/need, and types of shooting you typically do or need to do. At that early a stage of looking, it's certainly worth considering all options - You've most got them covered, though with a mix of older products. Nikon's D3000 and Canon's 1000D are older models, and there are better available from both. Olympus' E450 is also an older model as well, using their smaller micro 4/3 sensor. Pentax's KX is a little higher performing than the others you listed here, being of the newer sensor technology much more adept at higher ISO levels - comparable to Nikon's D3100, Sony's A500/550, and Canon's T2. And of course, the only one you're missing from the list is Sony - for which the entry-level A290/390 are probably comparable to the Nikon/Canon/Olympus models you listed, but behind the KX like the others in some specs.

Depending on your budget, the step up models (that I mentioned above) from each of the manufacturers would be better compared to the Pentax as far as low light performance, speed, continuous frame rate, and spec.

Which is why your budget is the most important piece of information, since new entry-level DSLRs run from the $400 range to the $1,400 range!

What do you want to do with your camera? Do you have any experience? What is your budget? Do you have much money to spend? Do you know that you have to spend 50% of your budget at the lens and 50% to the body itself?

i mainly want to use the camera for photos of my children and holidays, i take decent pictures with a normal digital camera but always wanted a sdlr camera, my budget is about £400 british pounds, i am open to any make really

That's a really difficult question to answer. I could argue that the best one is the one that feels most comfortable in your hands, the one with the most rugged build quality, the one with the best system of lenses and accessories, the manufacturer that offers you the preferred upgrade path to the next level of camera body and so on and so on...

I don't review cameras so I can afford to be quite biased sometimes, though I try not to be. I'm not a fan of the four-thirds standard as it always seemed perverse to me for a camera system to adopt a 4:3 picture aspect ratio when the world is going widescreen and I personally didn't like the feel of the Nikon DSLRs around at my then lowish budget when I chose between Canon and Nikon a few years ago. I chose Canon because I did like the feel of the 400D that I bought and it definitely fitted the bill in terms of upgradability for both body and lenses (see my Signature below for where I am now). However, if I was asked to choose between the 1000D and the K-x with no expectation of a significant body upgrade in the future and if the K-x felt comfortable in hand (very important) you know I might just opt for the K-x.

It's been well reviewed (here), it has more pixels but still has good low light capability, has a faster frame rate for continuous shooting and it does movies. And if there are a few extra pennies in the budget you should be able to find it as a two lens kit (Pentax K-x + 18-55mm + 55-300mm Lens) for under £500 compared to £349 for the K-x with the standard 18-55mm kit lens. While an extra £150 is a lot of money the Pentax SMC DA 55-300mm F4-5.8 ED Lens would cost £280 if bought separately (prices from Park Cameras).

OK, I've now upset the Canon, Nikon and Olympus guys but I'm sure they'll fight their corner vigorously, albeit with our customary CameraLabs good humour. Good luck with your decision.

OK...in your price range, I'd say the KX is one of the best bargains, assuming it has all the features you feel you'd want/need, isn't omitting any must-have feature, and feels comfortable in your hands.

Also worthy of possible consideration, at or very close to your budget, might be the Sony A450, which should be in the £420ish range. Or you might be able to step up to the Nikon D3100, but it's a little higher at £450-480 range at minimum. That's also around the minimum range for the Sony A33, which would also be worth a look. But the KX will undercut them all in price.

Another curve ball to throw out at you would be to consider the smaller format mirrorless hybrid cams - they are much much better than P&S cameras, in some cases as capable as DSLRs, yet much smaller and lighter...and the price would be on target. The Sony NEX3, and the Olympus Pen EP-L1 would both be under £400, and would easily handle light-duty travel, vacation, holidays, and around the house stuff. Plus, they have their own range of lenses available, have larger sensors just like the DSLR equivalents which allow them to perform in low light, and with various adapters can even handle just about any lens ever made.

A correction regarding the note about Olympus camera format -- the DSLRs are FourThirds and the mirrorless cameras are micro FourThirds. The sensor sizes are the same in both - it is the lenses and the lens mounts that are different. For more information on the FourThirds and Micro Four/Thirds standards, check out www.four-thirds.org.

Insofar as entry level cameras -- if you can stretch your dollar, consider the e-620. It is an outstanding value - especially the 2-lens kit. The e-420 is quite good, but does lack IS - which is valuable at low speeds (a key reason for the lenses being smaller/lighter in the 4/3 standard).

At the end of the day, the only way to tell is to get into a shop and handle your candidate cameras.

Ah yes...I knew that - I just got lazy, or brain farted and called the DSLR sensor a 'micro 4/3' - I'm so used to explaining the MIL cameras to folks that I've been saying micro a lot - it just stuck in my brain!